{ "[envelope].opening", UNDEFINED_FILENAME },
{ "[envelope].closing", UNDEFINED_FILENAME },
{ "invisible_sand.digging", "schlurf.wav" },
+ { "invisible_sand.active.digging", "schlurf.wav" },
{ "shield_normal.collecting", "pong.wav" },
{ "shield_normal.active", UNDEFINED_FILENAME },
{ "shield_deadly.collecting", "pong.wav" },